thermal spraying deposition efficiency.The ratio of theweight of thermal spray deposit to the weight of sur-facing material sprayed, expressed as a percentage.thermal spraying gun.A device for heating, feeding,and directing the flow of surfacing material.thermal spraying operator.One who operates auto-matic, mechanized, or robotic thermal spraying equip-ment. Variations of this term are arc sprayingoperator, flame sprayingoperator, and plasmaspraying operator.thermal stress. Stress in a material or assembly resultingfrom nonuniform temperature distribution or differen-tial thermal expansion.thermite crucible. The vessel in which the thermitereaction takes place.thermite mixture. A mixture of metal oxide and finelydivided aluminum with the addition of alloying metalsas required.thermite mold. A mold formed around the workpiecesto receive molten metal.thermite reaction. The chemical reaction between metaloxide and aluminum producing superheated moltenmetal and a slag containing aluminum oxide.thermite welding (TW). A welding process producingcoalescence of metals by heating them with super-heated liquid metal from a chemical reaction betweena metal oxide and aluminum, with or without theapplication of pressure. Filler metal is obtained fromthe liquid metal.thermocompression bonding. A nonstandard term for hotpressure welding.threading and knurling, thermal spraying. A methodof surface roughening in which spiral threads areprepared, followed by upsetting with a knurling tool.See Figure B.43(E). See also groove and rotaryroughening,knurling,androtary roughening.throat area, resistance welding.The region bounded bythe physical components of the secondary circuit of awelding machine.throat crack. A crack in the throat of a fillet weld. SeeFigure B.33.throat depth, resistance welding. The distance from thecenterline of the electrodes or platens to the nearestpoint of interference for flat sheets.throat height,resistance welding. The minimum dis-tance between the arms of the welding machinethroughout the throat area.throat length. A nonstandard term when used for con-stricting orifice length.throat of a groove weld. A nonstandard term for grooveweld size.throat opening. A nonstandard term for throat height.tie-in, n., fusion welding. The junction of weld metaland base metal or prior weld metal where fusion isintended.tie-in, v., fusion welding. To manipulate the welding pro-cess at the junction of the weld metal and base metalor weld metal to facilitate fusion.TIG welding. A nonstandard term for gas tungsten arcwelding.tinning. A nonstandard term when used for precoatingfor soldering.tip.See cutting tipand welding tip.tip skid. A nonstandard term for electrode skidding.T-joint. A joint type in which the butting end of a work-piece is aligned approximately perpendicular witheither its surface or the surface of a nonbutting work-piece. See Figures B.1(C), B.2(C), and B.10(F). Seealso skewed joint.
AWS A3.0M/A3.0:201044toe crack. A crack observed at the weld toe. See FiguresB.32(A) and B.33(A).